Kategorie: News
Greenhouse gases continue to heat the seas
Sea surface temperatures are rising faster than previously thought. A new study shows that ocean warming has accelerated dramatically in recent decades. While the temperature increase between 1985 and 1989 was still 0.06 degrees Celsius per decade, between 2019 and 2023 it was already 0.27 degrees – more than four times as much.
Until now, it was assumed that the temperature increase would be steady and linear. However, research led by Christopher Merchant of the University of Reading shows that warming has intensified in recent years. In particular, global sea surface temperatures reached record levels between April 2023 and July 2024. One important factor was the El Niño climate phenomenon, which caused an unusually strong warming of the Pacific. In the ocean regions between 60 degrees north and 60 degrees south latitude, temperatures were up to 0.31 degrees above the previous maximum values for the respective seasons.
The researchers used satellite measurements and climate models to analyse the causes of the warming. Their findings show that almost half (44 per cent) of the increase is due to man-made climate change – in particular, greenhouse gases such as CO₂ that accumulate in the atmosphere. Even though natural factors such as El Niño play a role, they are not the main driver of the development.
The study concludes that previous forecasts of ocean warming have been underestimated. If current trends continue, the global temperature increase of the sea surface calculated over the last 40 years will be exceeded within the next two decades. Merchant compares the process to a bathtub filling up with hot water: 40 years ago, the tap was only slightly open, but now the water is flowing in much more quickly. To slow down the warming, the ‘hot tap’ has to be turned off – this means drastically reducing global CO₂ emissions.
Link to the study: iopscience.iop.org/article/10.1088/1748-9326/adaa8a